When ever I wipe my macbook(and I've done it several times) is back up my photos, music and documents onto the ehd. Anything you can't download needs to go on the ehd.

Then I put in the disk and let it go from there, and the first thing I do is install all the software updates. Then download all your programs you used to have, and check for software updates again.

That's what I do and it works well for me.